diff --git a/index.php b/index.php
index 4a92433..a3dc5a5 100644
--- a/index.php
+++ b/index.php
@@ -1,43 +1,61 @@
 <?php
-// PHP startpunt (kan later scores / sessions doen)
+// later kan hier PHP score / sessions
 ?>
 <!DOCTYPE html>
 <html lang="nl">
 <head>
     <meta charset="UTF-8">
-    <title>T-REX</title>
+    <title>loading...</title>
 </head>
 <body>
 
-<h1>T-Rex Run (in de tab 😎)</h1>
-<p>Kijk naar de titel van dit tabblad</p>
+<h1>Kijk naar de tab 👆</h1>
 
 <script>
-let trex = "🦖";
-let ground = "____________________";
-let pos = 0;
-let dir = 1;
-let score = 0;
+// vaste dino positie
+const dinoPos = 5;
 
-function updateTitle() {
-    let before = ground.substring(0, pos);
-    let after  = ground.substring(pos + 2);
+// wereld (komma = obstakel)
+let world = "          ,        ,     ,        ";
+let jumping = false;
+let jumpFrames = 0;
 
-    // obstakel
-    let obstacle = (score % 10 === 0) ? "::" : "  ";
+function gameTick() {
+    // wereld schuift naar links
+    world = world.slice(1) + (Math.random() < 0.15 ? "," : " ");
 
-    document.title =
-        before + trex + after + obstacle + "  score:" + score;
-
-    pos += dir;
-    if (pos <= 0 || pos >= ground.length - 2) {
-        dir *= -1;
+    let display = "";
+    for (let i = 0; i < world.length; i++) {
+        if (i === dinoPos) {
+            // dino
+            if (jumping && world[i] === ",") {
+                display += ";"; // springt over obstakel
+            } else {
+                display += ".";
+            }
+        } else {
+            display += world[i];
+        }
     }
 
-    score++;
+    document.title = display;
+
+    // jump logica
+    if (jumping) {
+        jumpFrames--;
+        if (jumpFrames <= 0) jumping = false;
+    }
 }
 
-setInterval(updateTitle, 200);
+// space = jump
+document.addEventListener("keydown", e => {
+    if (e.code === "Space" && !jumping) {
+        jumping = true;
+        jumpFrames = 4;
+    }
+});
+
+setInterval(gameTick, 180);
 </script>
 
 </body>
